Does a jet engine run backwards when a plane lands?

Question

On a commercial jet, it lands, and you can feel it braking and slowing down. Are the jet engines providing the braking? Does that mean there is a point in time when the jet engines are stopped and then restarted in the opposite direction? I mean, do the turbines stop spinning and reverse directions at some point?

Is there a separate motor for the airplane when it is taxing on the runway?

Answer 1

The deceleration you have mentioned must be a combination of wheel braking and thrust reversal. Thrust reversal is achieved by vectoring the engines thrust at some angle against the direction of motion of the aircraft. Usually some deflection mechanism is employed to direct the engines thrust forward.

And no, there are is no power to the aircraft for movement other than the main powerplant(s) for taxiing.

Answer 2

I flew several models of commercial jets and this sounds like a MD-80 series (earlier models were DC-9s). Descents are almost always made with all engines at idle power. There is still thrust, but it is minimum for that speed and altitude. The engine near you would not have stopped even if the fuel were completely shut off. The engine will rotate from forward motion like a toy pinwheel at a speed about 25-50% of idle rpm. (If you have a vary rare "flameout" you can get a restart by applying ignition and fuel at the proper time just like at the gate.) The noise you heard was probably from the landing gear and flaps being extended for landing. This is quite noisy on some jets. On most MD-80s the seating is 2 on the left and 3 on the right as you face forward.

Answer 3

No, the engine can't "stop and reverse" what does happen is much like a propellor-driver plane when they slow donw, the blades of the turbine are rotated backward. So, instead of pulling air from the front of the engine, they are blowing it foward, reversing the direction of the thrust and slowing down the aircraft.
The brakes are also used to slow the plane, as are the flaps on the main wings. If you have ever seen a prop-driven aircraft "back up" that is exactly what is happening.

Answer 4

No, commercial jets do not employ a seperate engine for ground movement. They do employ thrust reversers to assist in braking when landing. Thrust reversers are simply devices designed to deflect the jet engine's thrust in a forward direction rather than toward the rear.

Answer 5

NO the engines do not stop and restart. There is a system of blocker doors that close over the fan section exhaust and redirect the air flow in a forward direction. On some older aircfraft there is also a blocker door sytem over the core engine.
NO there is no separate engine used for taxing. Taxing is done with the main engines.

Answer 6

Modern jet engines have what's called Thrust Reversers, which are basically self explanitory: two or more ports open up from the sides of the engine and redirect the thrust forward to slow the plane down.

Answer 7

Contrary to "popular belief", no engine, turboshaft/ prop or fan, turns in the opposite direction to produce reverse thrust. Turboprops can reverse pitch of the blades, not direction of rotation. On turbofans, you have cascade vanes and blocker doors, or clamshells. Cascades operate by the rear of the fan cowl sliding rearward. When it does this connecting arms pull the blocer doors open, which move air from the fan (not the core) to the cascade vanes. The vanes are exposed as the cowl slides open, and are fixed in position, but direct the air in a slightly forward direction.

Answer 8

When an aircraft land's, the propellers rotate in the opposite direction producing the opposite force required to reduce the speed of the aircraft. This action is called REVERSE THRUST.

Answer 9

No, they reverse the thrust by moving the rear part of the engine, you can see this happen if you look out the window.

Answer 10

the reverse thrust, and the try to create drag on the plan thats why the flap on the wings sticks up